Abstract:Push-rod dilatometer has been developed for measuring linear thermal expansion coefficients of solid
materials for thermal expansion from the room temperature to 500℃. The linear thermal expansion coefficients of single-
crystal sapphire have been determined using the Push-rod dilatometer. The present data are compared with the data
recommended by the National Institute of Standards and Technology ( NIST), which are in good agreement. The
relative uncertainty in the measurement was estimated to be less than 4% in the temperature range, based upon the
data of single-crystal sapphire.